During the last twenty-five years or so, there has been a dramatic shift in the packaging of beverages, such as bottled water and soft drinks, away from glass containers and toward plastic containers. Polyethylene terephthalate (PET) is in wide use throughout the world for such containers because it exhibits such preferred characteristics as high toughness, light weight, high transparency, high pressure resistance and acts as a good gas barrier.
PET containers are commonly hot-filled, i.e., when the containers are filled with a fluid, the product is above room temperature. After filling, the containers are cooled down with a water spray. Typically, these containers also have a central label area to which a product label, referred to as a shrink-sleeve label, is applied. A problem may arise, when water or other fluid invades the area between the container and the label and becomes trapped. When water or product does not drain from this area, the trapped fluid can spoil, stains can form and/or unpleasant odors can result. Therefore, any improvement that will tend to reduce or eliminate this problem is highly desirable.
One prior art container designed to reduce any potential for the accumulation of fluid is disclosed in commonly-assigned U.S. Pat. No. 8,988,417. This patent discloses a small groove that extends from inside the central label area of the container to an area slightly below the label area so that fluid can flow down and out from underneath a label. This exemplary prior art groove for drainage is recessed from the outer surface of the container, forming a pathway between a recessed vacuum panel in the central label area to the area below the label.
Another exemplary prior art container, which is sold in Japan, has a cross section as shown in FIG. 3. This cross section is taken at the level of the groove 8 just below the vacuum panels. This prior art groove 8 is completely recessed into the container, i.e., formed completely radially inward. This prior art groove 8, however, has the adverse effects of structurally weakening the container and sometimes buckling the container under vacuum conditions. It is, therefore, desirable to provide a drainage port that maintains the structural integrity of the bottle.
It is also desirable to provide drainage ports having a structure that may be readily and accurately reproduced by a hot-mold manufacturing process.